/*
 * Copyright (C) 2020 Graylog, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the Server Side Public License, version 1,
 * as published by MongoDB, Inc.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * Server Side Public License for more details.
 *
 * You should have received a copy of the Server Side Public License
 * along with this program. If not, see
 * <http://www.mongodb.com/licensing/server-side-public-license>.
 */
package org.graylog.plugins.views.search.rest.scriptingapi.response.decorators;

import org.graylog.plugins.views.search.permissions.SearchUser;
import org.graylog.plugins.views.search.rest.scriptingapi.request.RequestedField;

import java.util.HashMap;
import java.util.Map;

public class CachingDecorator implements FieldDecorator {

    private final FieldDecorator delegate;
    private final Map<CachingDecoratorKey, Object> cache = new HashMap<>();

    public CachingDecorator(FieldDecorator delegate) {
        this.delegate = delegate;
    }

    @Override
    public boolean accept(RequestedField field) {
        return delegate.accept(field);
    }

    @Override
    public Object decorate(RequestedField field, Object value, SearchUser searchUser) {
        final CachingDecoratorKey key = new CachingDecoratorKey(field, value, searchUser);
        if (!cache.containsKey(key)) {
            cache.put(key, delegate.decorate(field, value, searchUser));
        }
        return cache.get(key);
    }
}
